Morgan Creek Digital Assets issued a $1 million challenge that the fund’s cryptocurrency index would outperform the S&P 500 over the next decade. Founded by Anthony Pompliano and other crypto bulls, the challenge is the perfect opportunity for cryptocurrency doomsayers to “put their money where their mouth is.”

In a press release today, Morgan Creek Digital Assets publicized a bet that the Bitwise index fund of cryptocurrencies—including Bitcoin and altcoins—would outperform the S&P 500, a capitalization-weighted index of 500 of the largest U.S. publicly traded companies.

The bet is open to professional investors who either “believe cryptocurrencies are worthless,” or simply think that “public equities would be a better investment over the next decade.”